I still haven't sorted out the logistics of parts, and I haven't had the "final beta" PCB made and tested yet, but I wanted to put out a teaser of an upcoming addon:
A simple 8-bit digital I/O card!
This is not a card that allows connections to outside electronics, but a simple card where inputs may be given using push-buttons or DIP-switches, and output is presented on LEDs. The card uses a single IO address, selectable in the entire 8-bit range using the Address select DIP switches. This is a fairly large card considering what's on it, and could naturally have been smaller. The size is a full 100x100mm, and is an example of the typical size of a "standard-size" Z50Bus card.
Since then, a pre-production PCB has been spun, and I've made some adjustments. The pre-production PCB was designed for SIP resistor packs, but I went back to standard axial resistors to simplify logistics, reduce my part-catalog, and to make it "parts-bin pcb-only" friendly. Cost-wise axial resistors and SIPs would have been fairly similar in volume (8x 1 resistor vs 1x respack is about the same price).
I expect there to be some feedback on the design, but should warn you that I am very close to ordering the boards, and this was a product that was supposed to be available around the first week of june... On the other hand, this card is open sourced from the start, with the KiCad source files available already at
https://github.com/linc80/Z50IOCard
Speaking of dates. I expect to have a three-week lead-up to having the card available. If all goes well, I should have connectors and PCBs for the ROM-cartridge kits available around the same time, so all three products will "launch" at the same time.
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